1. Field of the Invention
The present invention relates to a data processing method, a data processing apparatus, and a recording medium, which are respectively capable of effectively utilizing computing resources of various apparatuses connected to a network constructed at home in particular.
2. Description of Related Art
Nowadays, as a result of construction of a communication network at home, personal computers (PC) and/or non-computer apparatus have been mutually connected to each other via a network. Such non-computer apparatuses include those conventional home information appliances such as a digital television set, a video cassette recorder (VCR), a set-top boxe (STB), and a robot. Further, such non-computer apparatuses also include a portable terminal unit such as a personal digital assistant (PDA) and a portable telephone set, for example. Any of these apparatuses has computing function and is capable of mutually exchanging data via a network. Further, any of these apparatuses is connected to the Internet via a gateway and capable of downloading various data and programs from one or more servers on the Internet.
Those apparatuses include such apparatuses containing allowance in terms of computing resources, such as CPU (central processing unit) function, a memory and a hard disk. These apparatuses will be called “resource-abundant apparatuses” in the following description. In addition, those apparatuses also include such apparatuses devoid of sufficient computing resources such as a PDA and a portable telephone, for example. These will be called “resource-scarcity apparatuses” in the following description. Any of these resource-scarcity apparatuses merely contains such computing resources just enough to sustain own functional capability.
In such a case in which such resource-scarcity apparatuses are mutually connected to those resource-abundant apparatuses via networks to be capable of communicating with each other, if it is possible for the resource-scarcity apparatuses to use computing resources of the resource-abundant apparatuses, the resource-scarcity apparatuses will potentially be able to exert such capability beyond its original function. Further, if it is possible to offer computing resources proper to the resource-abundant apparatus to the resource-scarcity apparatuses, it will become possible to integrally and effectively utilize such computer resources present in a domestic network.
For example, if a hard-disc stored in a personal computer is offered to a PDA, in other words, if the PDA is allowed to use some area of the hard disk of the PC, the PDA will be able to preserve image data beyond the original memory capacity of the PDA in the hard disk of the PC. Further, if a portable telephone is allowed to use a CPU of the PC, that is, computing capability of the CPU, it becomes possible for the portable telephone to execute more complicated and greater-size programs. Nevertheless, there is still a problem that there has been no practical means for allowing the resource-scarcity apparatus to use computing resources proper to the resource-abundant apparatuses to the resource-scarcity apparatuses in the conventional domestic network environment.
For example, conventionally, there have been such technologies titled as “Jini” (one of registered trade marks of Sun Microsystems Inc., U.S.A.) and “UpnP” (Universal Plug and Play) in software frame works dealing with such network environment constructed with non-computer apparatuses. Nevertheless, even though any of the above software frame works is fitted with a mechanism for automating initializing mechanism pertaining to connection between apparatuses, there has been a critical problem that the software frame works still fail to support a function pertaining to control of resources after implementing mutual connection between them.
In a conventional distribution computer system utilized in an office of a business enterprise and a laboratory of a university, which comprises a plurality of computers, there is provided a resources management mechanism in which the capacity of hard disk drives of servers are shared by other computers. A computer system within a domestic network system (hereinafter, referred to as “domestic network system”) can be considered to be a kind of distributing computer system. It is also possible to utilize a technique used in the conventional distributing computer system in the domestic network system.
Nevertheless, such a conventional distributing computer system does not take two important characteristic features inherent in the domestic network system into account. The first characteristic feature is that the distributing computer system is solely utilized by specific users. In other words, only members in a family share the apparatuses and exchange data via the network. Because of this, there are various requirements different from one family to another. For example, it is conceived that there is a specific demand in such a family including a member interested in video editing as to make a priority in the communication between a VCR and a personal computer utilized for editing video to be higher than a priority given in another communication between other apparatuses. In many cases, such a demand from a user is not generated until the user operates proper function of the domestic network system via connection of related apparatuses.
The second characteristic feature of the domestic network system is that physical variation in a status of apparatuses occurs frequently. The physical variation in the status of the apparatus implies variation related to connection to and disconnection from the network. Inasmuch as domestic network system contains many movable apparatuses and power source is frequently turned ON and OFF, such variation caused by disconnection of apparatuses from the network followed by recovery of connection thereto frequently occurs. In a case of the domestic network system, even when apparatuses connected to the network ever incurs the above physical variation, such services including proper control of resources should be preserved continuously.
For example, a case may be realized that a mechanism in which a PC, instead of a PDA, collects data frequently accessed by a certain device, is combined with a resource management mechanism so as to hold the latest version of data in a hard disk area of the PC, which the PDA is allowed to use. It is desired that the system is not dependent on a physical condition of the PDA. In other words, it is desired that this system should be operated continuously even when the PDA is disconnected from the network.
It is essential that the above system under operation is able to properly cope with a demand from a user and physical variation of an apparatus as described above. That is, the system is required to dynamically cope with user's demand and physical variation of apparatuses. Such function compatible with user's demand and physical variation of apparatuses is called “dynamic adaptability”.
Since none of conventional domestic network systems has ever taken the above-mentioned characteristic features, whenever devising to incorporate the dynamic adaptability, a critical problem is always generated in that complicated and ineffectual works are required by way of individually changing a basic structure of a server system in correspondence with each device and function, for example.